Tubular strings can become stuck in wells due to a variety of causes. One cause is differential pressure, with fluid pressure in a wellbore being greater than pressure in a surrounding earth formation. If a tubular string, such as drill pipe, is pressed against a wall of the wellbore, so that the differential pressure from the wellbore to the formation acts on the tubular string, it can be very difficult to move the tubular string away from the wall of the wellbore, so that the tubular string can be freed. This is known to those skilled in the art as differential sticking.
It will, thus, be readily appreciated that improvements are continually needed in the art of freeing pipe stuck in a well.